The present invention relates to particle sizing and more particularly to adjusting sands for particular applications such as use in concrete sand or asphalt sand or filter sand.
Particulate materials normally comprise a size distribution with size cuts, according to the U.S. standard Mesh sizes of 200 mesh, 100 mesh, 50 mesh, 30 mesh, 16 mesh, 8 mesh, and 4 mesh (per inch) and a 3/8-inch spacing between mesh size. A sieve analysis includes running a grab sample through a series of test sieves of such sizes and measuring the percent retained on each of the sieves. An additional indicator, called fineness modulus (F.M.) is the summation of accumulated weight percentages retained on the successive sieves yielding a number in excess of 100 percent, and divided by 100 percent to produce a number which is usually on the order of 2.01-3.50. F.M. indicators are usually confined to concrete sands and do not include the 100.times. 200 mesh value. Asphalt and mason sand FM indicators as I have invented, do include the 100.times. 200 mesh value. The invention is applicable to particles of all kinds including sands, ores, abrasives and other mineral and metal powders and food kernals, crumbs, oats, seeds and grains.
Very often particle handling processes, more particularly for sands, are run very inefficiently in that there may be excessive classification and blending, or in the alternative waste, because a specific application, such as concrete making or asphalt requires a closely defined sieve analysis and fineness modulus for the particular material (sand) used.
It is an important object of the invention to overcome such difficulties of the prior art and provide efficient materials usage.
It is a further object of the invention to provide a simple process for particulate material handling in the quarry, warehouse or the storage area, consistent with the preceding object.
It is a further object of the invention to accommodate blends as well as single feeds, consistent with one or more of the preceding objects.